I learned the hard way that my 2006 F150 with the 3 Valve 5.4 engine uses a variable timing system that reads off the oil pressure. The engine had 150000 miles on it, but always runs great. I changed the oil before a trip with my small 5th wheel and got into traffic and the truck began stumbling and died. Fired right back up and ran fine about 1000rpm, just would not idle. I found solution in posts that it was the oil pressure dropping too low (below 25 lbs) which caused the timing to change, so posting advice was to put in a slightly heavier weight oil, which solved everything immediately. As I am looking to buy a 2009 or later F350 Super Duty 2WD Dually with a V-10 and want to know, does this engine have the two piece spark plug problem or the variable timing/oil pressure issue like the 5.4?
Last edited by Pool Guy 23; 04-22-2014 at 09:39 PM.
Oil activated VVT does work, just look at 2000+ Corolla, and many others. Ford just dropped the ball adding it to their great modular motors. Again, so glad they left the V10 out! I Wonder why they omited it anyway?